THE PURPOSE OF THE STUDY WAS TO COMPARE THE EFFECTIVENESS OF (1) LECTURE PRESENTATIONS, (2) LINEAR PROGRAM USE IN CLASS WITH AND WITHOUT DISCUSSION, AND (3) LINEAR PROGRAMS USED OUTSIDE OF CLASS WITH INCLASS PROBLEMS OR DISCUSSION. THE 126 COLLEGE STUDENTS ENROLLED IN A BACTERIOLOGY COURSE WERE RANDOMLY ASSIGNED TO THREE GROUPS. IN A SUCCEEDING COLLEGE TERM 109 STUDENTS WERE ALSO RANDOMLY ASSIGNED TO THREE GROUPS. ALL STUDENTS HAD ACCESS TO TEXTBOOKS AND ATTENDED WEEKLY LABORATORY SESSIONS. THE 807-FRAME LINEAR PROGRAM WAS WRITTEN FROM THE LECTURE MATERIAL OF THE INSTRUCTOR AND INCLUDED SECTIONS ON (1) ANTIBIOTICS, (2) MICROBIOLOGY OF WATER, MILK, SOIL, AND SEWAGE, AND (3) INDUSTRIAL MICROBIOLOGY OF MILK PRODUCTS AND FOOD SPOILAGE. PRE-TEST SCORES ON THE FIRST ONE-THIRD OF THE COURSE WERE USED AS AN ADJUSTED VARIABLE IN COVARIANCE ANALYSIS OF SCORES ON POST-TEST SCORES. THE RESULTS IN BOTH TERMS CORROBORATED THE FINDING THAT LINEAR PROGRAMED MATERIALS WERE AS EFFECTIVE AS LECTURES. STUDENTS WHO EXPRESSED PRIOR CONFIDENCE IN PROGRAMED MATERIALS DID NOT MAKE HIGHER SCORES. PROGRAMED MATERIALS WERE EQUALLY EFFECTIVE UNDER EACH CONTROL. THIS PH.D. THESIS, WHICH WAS SUBMITTED TO THE PENNSYLVANIA STATE UNIVERSITY, IS AVAILABLE AS 64-10,785 FOR $2.75 ON MICROFILM AND FOR $8.60 AS XEROXED COPY FROM UNIVERSITY MICROFILMS, INC., 300 NORTH ZEEB ROAD, ANN ARBOR, MICHIGAN 48106. THE STUDY WAS SUMMARIZED IN VT 001 341. (JM)